As a reviewer, I often find myself wrestling with meaning. What did a piece mean, what was it trying to say? Was its phonetic and morphological structure sound enough to convey its message? In immersive theatre, often badly and gratuitously done, one must ask this question with especial rigour.

The Soulless Ones, the first immersive theatre piece from the iconic Hammer House of Horror – surely no introduction needed – is the third time I have seen an immersive production bill itself as being across four floors. The other two are worth comparing. In 2013, Punchdrunk staged their legendary immersive piece The Drowned Man across four floors of a former postal sorting office. Intricate, seductive and dazzlingly complete, it was immersive theatre at its most paradigm-defining, working hard to create the idea of an alternate reality that encouraged theatre patrons to confront their idea of what ‘theatre’, ‘audience’ and ‘fourth wall’ meant (though it did not impress every person walking through the famous red doors).

In 2014, Secret Theatre Project produced a dreadful adaptation of se7en, in a four-floor member’s club that had nothing to do with the storyline, where the immersion was approximately at the level of a funfair scare maze without the subtlety or the narrative consistency; it felt like a cynical attempt to cash in on the label ‘immersive’. I have long treated these two productions as benchmarks for what immersive theatre can mean, at either end of the scale.

Where does The Soulless Ones fall on this scale? In terms of intent, I don’t think Hammer House of Horror are being much less cynical than Secret Theatre Project. It is October, the month of Halloween, and people are keen to have Experiences with a capital E. There is absolutely no emotional subtlety, chance for deep engagement, or even any particular artistic meaning to The Soulless Ones’ immersion. It is pure entertainment.

However, in terms of execution, The Soulless Ones is much closer to Punchdrunk’s game-changing offerings – and owes a lot to Punchdrunk’s model of allowing the audience to wander freely throughout the building, giving them the choice of which performer to follow. It does do away with Punchdrunk’s 1:1s – where a performer takes a single audience members into a locked room and creates a scene especially for them – thus minimising the competition, elbow-barging and insistence on being the ‘best’ follower that was sometimes present during the run of The Drowned Man, but also minimising the chance to emotionally connect with any of the operatically flamboyant cast.

Replete with gorgeous Gothic sets (including a graveyard, at least two decadent boudoirs, a secret altar and a room filled with haunting puppets), marvellously melodramatic costumes, a ridiculous and enormously enjoyable script, and, above all, so much high camp I could have pitched a marquee with the atmosphere, The Soulless Ones is a daft delight. If you were a teenage goth, if you ever watched the Hammer Horror films, if you secretly read your horoscope, or if you just really, really want to run around pretending you’re a vampire, The Soulless Ones is for you.

There are so many characters in the piece, each with their own storyline, that it is impossible to describe everything that happens, because it’s simply not possible to see it all. However, the core storyline is this: audience members have been invited to a ‘hive of vampires’ nesting in Hoxton Hall by Nathaniel Blythe (Stephen Fewell, playing both patrician and putz in one superbly high colour swoop), a discredited Victorian occultist. He has also invited the opium addled poet Remy (Samuel Collings, a wittily pseudo-Byronic asshole), cynical doctor Cresswell (Phillip Edgerley) and up-and-coming psychic/tormented young woman Loveday (Roslyn Hill).

It becomes clear, once the audience are allowed to roam the unhallowed halls, that Blythe has tricked this unfortunate trio into coming for his own nefarious purposes. Carmilla (a splendidly robed, impressive and utterly one-dimensional Kate Sissons), head of the vampires and queen of the hive, needs the humans to complete a murderous ritual that will allow the vampires to walk in sunlight. As recompense, Carmilla has promised Blythe a vampire bride, Elodie (flounce-meister general Charlotte Blackledge) and the chance to become one of them. It takes approximately ten minutes to work out that Blythe has been lied to and used, but his self-deceiving hubris is fun to watch anyway. Matters are complicated by the fact that Loveday is a genuine medium, who is able to (unwillingly) channel something called Abbadon, which means the vampires nothing but harm.

The acting is at the approximate pitch of someone using a megaphone to shout Gothic poetry into your face – with the exception of a strange, Pierrot-like character named Dimi (Robert Nairne), whose story is sad, funny and painful. The script itself is just silly. It’s not frightening at all, and sensible forgoes the jump scares. But I don’t think any of this damages The Soulless Ones, as long as you know what to expect (and know that you have to walk around the place and commit to a storyline or two to do it). This is a great piece of camp horror, and a well-designed and aesthetically rich work of immersive theatre.

Hammer House of Horror Live: The Soulless Ones is on until 31 October 2017 at Hoxton Hall. Click here for more details.